React JS set focus on a input

Use the prop autoFocus in a input to make it auto focus

eg:

<input autoFocus className="btn" type="text" />

React JS send custom parameter to onClick

If you need to send a custom parameter to your onClick event handler, do like this

<a href="" onClick={()=> {this.tabClicked("Exceptions")}}>Exceptions</a>

if you need to pass the event as well to the onClick handler use like this

<a href="" onClick={(evt)=> {this.tabClicked(evt,"Exceptions")}}>Exceptions</a>

and in your tabClicked() you can get the parameters like this

tabClicked(evt, tab) {

evt.preventDefault(); // Let's stop this event.

alert(tab); // should alert Exceptions

}

Bootstrap 4 to Bulma conversion table

Bootstrap 4 class	Bulma class
.rows	.columns
.col	.column

Bootstrap - show text in a single link

To show text in a single line you need to added the Bootstrap class "text-nowrap"

Example

<span class="nowrap">Your text here.</span>

JavaScript - Check if object is empty

function isEmptyObject ( obj ) {
    var name;
    for ( name in obj ) {
        return false;
    }
    return true;
}

JavaScript set object key by variable

ES6

var key = "name";
var person = {[key]:"John"};
console.log(person); // should print  Object { name="John"}

Before ES6

var person = {};
var key = "name";

person[key] /* this is same as person.name */ = "John";

console.log(person); // should print  Object { name="John"}

Give random colors to text in a page using D3

d3.selectAll("*").style("color", function() {
  return "hsl(" + Math.random() * 360 + ",100%,50%)";
});